Today, two cinematic technologies are in use, analog (conventional film) and digital. While digital cinema technology may soon eclipse film use in the industry, it is advantageous to explore the benefits of both and make the best use of the two technologies currently available. The invention described here does this by combining a specific film format for the capture of images (acquisition) and digital projection for exhibiting those same images. In the method to be described, a “best of both” result is achieved.
Sometimes an older technology can store more information than it can recover and display. As an example, early (before 1925) sound recordings were made acoustically. The recording process actually imparted more sound information onto the record than acoustical playback could reproduce. The capability was not known until electrical amplifiers became the “new” playback technology in the 1920s. People listening to acoustically-recorded phonograph records through an electrical playback system experienced a palpable improvement when listening to acoustically-recorded records, compared to playing the same records acoustically.
Similarly, it has been demonstrated that the information storage capacity of film as a medium for the acquisition of photographic images can exceed the amount of information that conventional film projection can display. Accordingly, it is the primary objective of this invention to combine image acquisition through use of film with image exhibition by digital means, so that the full information storage capacity of film can be successfully displayed to theatrical motion picture audiences. In short, using today's most modern color film with the latest emulsions available allows sufficient information storage to deliver information packing density comparable to photography in a larger film format, or digital photography with a large pixel count, as practiced in the conventional art.
The native resolution of contemporary 35 mm film, in the 2-perforation format used in the practice of the invention, along with digital post-production, is sufficient to allow it to be used effectively for digital projection at 48 frames-per-second in the 2K level of content (1080 pixels high and 2048 pixels wide). In practice, the native resolution of the 35 mm, 2-perforation format is sufficient to produce a viewing experience comparable to that delivered by film projection in the historical 70 mm, 5-perforation, format at 24 frames-per-second. Images processed at 2K and 48 frames-per-second produce comparable temporal and spatial resolution to 4K. This comports with the requirements of contemporary motion picture theater installations, where screens are often at least 50 feet wide, and can be up to 90 feet wide.
The film format used in the preferred embodiment of the invention is 35 mm with two perforations per frame. The resulting image is this format is only half the height of the conventional 35 mm (4-perforation) image. This format, known in the 1960s as Techniscope, had the advantage of being able to capture a film image with only half the amount of film required to capture the same image on conventional 35 mm (4-perforation format) film. The image size was 0.868 by 0.373 inches or 22 by 9.46 mm in the 2-perforation format. In the invention described here, use of the 35 mm, 2-perforation format not only improves economy of production, but it also facilitates “shooting” operations by allowing twice as many images to be recorded on the same amount of film stock as could be achieved with conventional 35 mm film.
The Techniscope format did not use the entire width of the film strip between the rows of sprocket holes, to allow for the preferred aspect ratio. A later format, developed by Panavision, Inc., featured a slightly larger image than Technicscope, but also did not use the entire width available for picture information. If the full width had been used, as is proposed in the invention described here, an aspect ratio in the range of 2.35:1 to 2.4:1 (comparable to CinemaScope) to as wide as 2.61:1 (comparable to Cinerama) could be achieved.
A 35 mm, 2-perforation format has been used before, but not with the results that the present invention delivers. The original Techniscope format from the 1960s required anamorphic expansion for CinemaScope (aspect ratio of 2.4 to 1) presentation, but saved on the cost of raw film stock. That method was cost-effective, but the quality of presentation was not as good as that available with the conventional 35 mm, 4-perforation format.
The format was originally used to double the amount of time during which photographic images could be captured on a single camera load, resulting in the economical use of film stock. A standard 35 mm raw stock roll contains 1000 feet of film. At twenty-four frames per second, the film travels at a rate of 92 feet per minute, for a potential shooting time of 10 minutes and 52 seconds. Use of the 2-perforation format permits 21 minutes and 45 seconds of action to be captured on the same roll of film in the conventional art. The present invention requires that forty-eight images be photographed every second. Using the standard 4-perforation format for 35 mm film, a 1000-foot roll could permit shooting for only slightly more than five minutes. With the 2-perforation format as described, a roll of film allows as much shooting time as can be obtained through use of the 4-perforation format in twenty-four frame-per-second photography. Accordingly, it is an objective of the present invention to achieve the economy and operational improvement available with the 2-perforation film format in a contemporary operating scenario with state-of-the art exhibition methods at forty-eight frames per second. The improved economy in consumption of film stock also delivers the additional benefit that it is not necessary to change film as often when the format described here is used for 48-frame-per-second capture, compared to the conventional 4-perforation 35 mm or larger film formats. When a film magazine can accommodate twice the shooting time than is available at 48 frames per second with the conventional format, it is necessary to change film in the camera only half as often. This allows longer scenes to be photographed, as well as saving on effort and costs of labor.
Since the 1960s, the 2-perforation format has been used for two applications, economy of film use and three-dimensional (3D) presentation. With its aspect ratios in the range of 2.35:1 to 2.4:1, it saw use in production of motion pictures for exhibition in anamorphically-projected wide-screen formats. Images were stretched to the 4-perforation aspect ratio in an optical printer for storage in the conventional 4-perforation 35 mm format, and then anamorphically stretched in the horizontal direction to deliver a wide-screen CinemaScope-compatible presentation. The format was also used for three-dimensional presentation with successive images shown for the left eye and right eye, known as “over and under” format. The 2-perforation format lent itself to 3D, since each image for the left eye, in addition to its companion image for the right eye used the same amount of film stock as a conventional motion picture in 35 mm film format. The invention uses much of the structure of digital cinema 3D presentation known in the art, but modifies it to produce a result that delivers an improved, but different, presentation compared to 3D exhibition as known in the art. The current invention uses a progressive frame display to render a 48-frame-per-second presentation, rather than alternating frames for each eye, 24 right and 24 left, as is done for 3D presentation.
Today, film is capable of storing more information than was possible in the 1960s. The resolution level of contemporary motion picture film is considerably greater than the capability of film then in use. In addition, digital techniques now known in the art produce more efficient image transfer than was available at the time. Digital image treatment can also improve image sharpness while removing undesirable artifacts, such as grain and instability, to name just two. Therefore, digital imaging and exhibition techniques can deliver more picture information to a theatrical motion picture audience using images acquired in the 35 mm, 2-perforation film format than could be delivered to audiences of the past, utilizing the film techniques in effect when the format was initially used.
The invention described here is a hybrid process, using both film and digital techniques; film for image capture, and digital techniques for post-production and projection. After the images are photographed on film, they are scanned, to convert them to digital images. All steps occur at the frame rate of 48 frames-per-second in the preferred embodiment of the invention.
Yoshida, U.S. Pat. No. 3,637,297, developed his 35 mm 2-perforation film system that used the same image areas as Techniscope in 1965. Because of the improved quality of contemporary motion picture film, compared to that available when Yoshida reduced his invention to practice, there are a number of advantages available today, through image capture in the film format described in the present invention. Much of the Yoshida invention was based on new cameras and projectors designed for photography and presentation of film in his format, which still did not use the entire image area, from sprocket hole to sprocket hole, as the present invention does.
The available width of the film format used in the present invention allows an aspect ratio as wide as 2.61 to 1, which is comparable to that used in Cinerama, if the entire frame is filled with picture information, from sprocket hole to sprocket hole. The level of spatial and temporal resolution available with the invention, using the frame rate of 48 frames-per-second, is comparable to or exceeds that available at 24 frames-per-second with either 35 mm conventional film or digital post-production and projection at 24 frames-per-second. The viewing experience available with this invention also exceeds that available with 70 mm, 5-perforation film at 24 frame-per-second projection, which has long been recognized as the industry standard for high-performance theatrical motion picture exhibition.
One of the original uses of the 2-perforation format was to store 24 images for each eye, photographed during each second, for a 3D “over and under” presentation. Thus, the preferred format for the present invention can also store 48 discrete images per second on the same amount of film stock that was conventionally used to store 24 images per second. The advantages of film projection at 48 frames per second were demonstrated in Weisgerber, U.S. Pat. No. 5,627,614 (1997). Similar advantages at other frame rates were demonstrated in Weisgerber, U.S. Pat. No. 5,739,894 (1998). These advantages included smoother interpolation of motion than was available with the convention 24-fps frame rate, suppression of flicker and ability to use a significantly brighter light (17 footlamberts or more) than was possible through conventional exhibition methods (12 to 16 footlamberts). Weisgerber 614 also taught a method for alternating between scenes or film sequences that deliver a “high-impact” look and other scenes or sequences yielding a traditional “cinematic” look, within the same motion picture. Weisgerber has also developed a method for converting motion pictures photographed at twenty-four frames per second for projection at forty-eight frames per second, with the benefit that the films so produced deliver the visual benefit of exhibition at the higher frame rate. (Weisgerber: Method for Exhibiting Motion Picture Films at a Higher Frame Rate than that in which which they were Originally Produced, U.S. patent application Ser. No. 11/478,940, filed Jun. 30, 2006 and continuations-in-part.
Demonstration of the invention described here has shown that digital exhibition at the rate of forty-eight images per second (equivalent to projection of film at forty-eight frames per second) produces a “dimensional” effect on the viewers of motion picture displayed at that speed. This is not equivalent to a 3D presentation, but it does add effects that go beyond the flat appearance of conventional two-dimensional (2D) film presentation at twenty-four frames per second. This dimensional illusion is inherent in the high rate of image delivery. It is, therefore, an objective of the present invention to deliver the advantages made possible by the techniques taught in Weisgerber 614 through the use of digital motion picture exhibition methods.
The net result of the use of this invention is to produce a superior cinematic product, in an economical manner, which delivers a viewing experience to the audiences of such motion pictures that was not previously available. The end product is a value-added presentation that draws audiences into motion picture theaters, while allowing motion pictures to be produced more economically than is the current industry practice.